A rod lens system is used in endoscopes to image an intermediate image, lying in a distal intermediate image plane, of an object to be observed by means of the endoscope into a proximal intermediate image plane and thus to relay the intermediate image.
As a rule, such rod lens systems have repeating rod lenses in symmetrical reversal stages, in order to keep the costs of the overall system low. Identical rod lenses are installed in opposite directions. This leads to the problem that a longitudinal chromatic aberration caused by the rod lens system can only be corrected with difficulty.